Down-regulation of HSP60 Suppresses the Proliferation of Glioblastoma Cells via the ROS/AMPK/mTOR Pathway.
Down-regulation of HSP60 Suppresses the Proliferation of Glioblastoma Cells via the ROS/AMPK/mTOR Pathway.
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HSP60 的下调通过 ROS/AMPK/mTOR 途径抑制胶质母细胞瘤细胞的增殖
DOI：
10.1038/srep28388
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发表时间：
2016-06-21
影响因子：
4.6
通讯作者：
Deng H
中科院分区：
文献类型：
--
作者：
Tang H;Li J;Liu X;Wang G;Luo M;Deng H
胶质母细胞瘤是一种致命的、无法治愈的癌症，具有高度激活的mTOR通路。HSP60是维持线粒体蛋白平衡的主要伴侣蛋白，在胶质母细胞瘤患者中高表达。为了了解HSP60在胶质母细胞瘤发生和发展中的作用，我们对HSP60基因敲除的胶质母细胞瘤细胞进行了鉴定，发现HSP60沉默显著抑制了细胞的增殖，并促进了细胞经历上皮-间充质转化(EMT)。蛋白质组学分析表明，在HSP60基因敲除的U87细胞中，核糖体蛋白显着下调，而EMT相关蛋白则上调，叠氮高丙氨酸标记的新合成蛋白的明显富集型证实了这一点。生化分析表明，HSP60基因敲除后增加了导致AMPK激活的活性氧(ROS)的产生，类似于复合体I抑制剂鱼藤酮诱导的AMPK激活。激活的AMPK抑制mTORC1介导的S6K和4EBP1的磷酸化，减少蛋白质翻译，从而减缓细胞的生长和增殖。另一方面，在HSP60基因敲除或鱼藤酮处理的U87细胞中，高水平的ROS有助于EMT。这些结果表明，HSP60的沉默抑制了mTOR通路，从而抑制了胶质母细胞瘤的进展，表明HSP60是治疗胶质母细胞瘤的潜在靶点。
Glioblastoma is a fatal and incurable cancer with the hyper-activated mTOR pathway. HSP60, a major chaperone for maintenance of mitochondrial proteostasis, is highly expressed in glioblastoma patients. To understand the effects of HSP60 on glioblastoma tumorigenesis and progression, we characterized the HSP60-knockdowned glioblastoma cells and revealed that HSP60 silencing markedly suppressed cell proliferation and promoted cell to undergo the epithelial-mesenchymal transition (EMT). Proteomic analysis showed that ribosomal proteins were significantly downregulated whereas EMT-associated proteins were up-regulated in HSP60-knockdowned U87 cells as confirmed by a distinct enrichment pattern in newly synthesized proteins with azido-homoalanine labeling. Biochemical analysis revealed that HSP60 knockdown increased reactive oxygen species (ROS) production that led to AMPK activation, similarly to the complex I inhibitor rotenone-induced AMPK activation. Activated AMPK suppressed mTORC1 mediated S6K and 4EBP1 phosphorylation to decrease protein translation, which slowed down cell growth and proliferation. On the other hand, high levels of ROS in HSP60 knockdowned or rotenone-treated U87 cells contributed to EMT. These results indicate that HSP60 silencing deactivates the mTOR pathway to suppress glioblastoma progression, suggesting that HSP60 is a potential therapeutic target for glioblastoma treatment.